Currently, flexible display devices, including flexible organic light emitting diodes (OLEDs), flexible liquid crystal displays (LCDs), flexible electronic papers, and the like are manufactured with a commonly used manufacturing method: coating or adhering on a rigid substrate (typically a glass substrate) a flexible film substrate; and after a display device is formed, peeling the flexible film substrate with the display device from the rigid substrate. Polyimide (PI) is often used as a flexible film substrate in flexible display devices because it is a high-quality, high-temperature flexible material. There are two methods for peeling a polyimide flexible film substrate from a rigid substrate, one of which is laser peeling, and the other is mechanical peeling. Laser peeling requires dedicated laser equipment, which involves a huge investment, consuming a long time, and is difficult to ensure evenness. Mechanical peeling is relatively simple, but requires control on the peeling force, otherwise it will damage the display device.